When Both Transmitting and Receiving Energies Matter: An Application of Network Coding in Wireless Body Area Networks

A network coding scheme for practical implementations of wireless body area networks is presented, with the objective of providing reliability under low-energy constraints. We propose a simple network layer protocol for star networks, adapting redundancy based on both transmission and reception energies for data and control packets, as well as channel conditions. Our numerical results show that even for small networks, the amount of energy reduction achievable can range from 29% to 87%, as the receiving energy per control packet increases from equal to much larger than the transmitting energy per data packet. The achievable gains increase as a) more nodes are added to the network, and/or b) the channels seen by different sensor nodes become more asymmetric.Comment: 10 pages, 7 figures, submitted to the NC-Pro Workshop at IFIP Networking Conference 2011, and to appear in the conference proceedings, published by Springer-Verlag, in the Lecture Notes in Computer Science (LNCS) serie

Graphic trace analysis of ultrasound at the phalanges may differentiate between subjects with primary hyperparathyroidism and with osteoporosis: a pilot study

Bone loss characterizes both primary hyperparathyroidism (PHPT) and osteoporosis (OP) but with a different histologic pattern, and this could partially explain the different fracture incidence in these two populations. Quantitative ultrasound (QUS), influenced by bone structural parameters other than bone mineral density (BMD), could evidence these differences, opening new perspectives in the evaluation of patients with metabolic bone diseases. The aim of the present study was to investigate the usefulness of QUS graphic trace parameters, assessed at the phalanx, in discriminating between PHPT bone disease and osteoporosis. We studied 34 patients with PHPT (mean age 59.7 +/- 12.7 years), 35 patients with OP (mean age 60.6 +/- 7.1 years) and 34 healthy subjects as controls (mean age 59.1+/- 9.4 years). In all subjects QUS measurements were performed at the phalanx with a Bone Profiler (IGEA, Italy), obtaining the amplitude-dependent speed of sound (AD-SoS), fast wave amplitude (FWA), signal dynamic (SDy), bone transmission time (BTT) and ultrasound bone profile index (UBPI). Moreover, serum calcium, phosphorus, parathyroid hormone (PTH), bone isoenzyme of alkaline phosphatase (B-ALP) and ionized calcium were measured in all subjects in the morning under fasting conditions. In PHPT patients BTT was correlated with PTH, ionized calcium and B-ALP levels (r = -0.47, -0.57 and -0.44, respectively; p < 0.01), whereas FWA, SDy and UBPI correlated only with B-ALP (r = -0.43, -0.46 and -0.50, respectively; p <0.01). Moreover, FWA, SDY and UBPI were significantly (p<0.01) lower and BTT significantly (p<0.001) higher in OP than in PHPT patients. UBPI, BTT, FWA and the BTT/FWA ratio, but not SDy, were able to discriminate between the two groups (area under the curve =0.66, 0.69, 0.67 and 0.81, respectively). Our findings show that ultrasound signal parameters are differently influenced by bone changes characterizing primary hyperparathyroidism or osteoporosis. This suggests that the QUS signal could be a useful instrument in discriminating and studying some of the bone alterations typical of metabolic bone diseases

Direct oral anticoagulants in patients affected by major congenital thrombophilia

Background: Thrombophilia is a condition that predisposes to a higher incidence of venous thromboembolisms (VTE), some also in atypical sites. Direct oral anticoagulants (DOACs) have proven to be effective in the treatment of deep vein thrombosis (DVT). However, their use can be sometimes challenging in particular settings of patients such as those with major thrombophilia - antithrombin, protein C and protein S deficiency, homozygous mutation of Factor V Leiden, homozygous mutation of Factor II G20210A, combined heterozygous mutation of factor V Leiden and Factor II G20210A - carrying a high thrombotic risk. Patients and Methods: At our Center, 45 patients with major thrombophilia were treated with DOACs: 33 after an initial treatment with vitamin K antagonists (VKA) and 12 as first-line therapy for VTE. The median follow-up of DOACs treatment was 29 months. Conclusions: No patient presented hemorrhagic or thrombotic complications during DOAC therapy. DOACs have proven to be effective and safe in this real-life series of patients with major thrombophilia

Pharmacokinetic profile and effect on bone markers and muscle strength of two daily dosage regimens of calcifediol in osteopenic/osteoporotic postmenopausal women

Background: At present, although cholecalciferol represents the form of vitamin D of choice for the treatment of vitamin D deficiency, there is a growing interest in calcifediol. Aims: This study aimed to evaluate the efficacy and the safety of two different daily doses of calcifediol. Methods: Fifty osteopenic/osteoporotic women with serum levels of 25-hydroxyvitamin D (25OHD) between 10 and 20&nbsp;ng/ml were randomized to a 6-month treatment with oral calcifediol 20&nbsp;µg/day (n = 25) or oral calcifediol 30&nbsp;µg/day (n = 25). In all, we measured the time course of the levels of 25OHD and other biochemical parameters. Moreover, we evaluated handgrip strength and serum levels of myostatin. Results: The peak increase in 25OHD levels was reached after 90&nbsp;days of treatment in group 1 (59.3&nbsp;ng/ml) and after only 60&nbsp;days in group 2 (72.3&nbsp;ng/ml); thereafter in both groups, the levels of 25OHD showed a tendency towards stabilization. After 30&nbsp;days, all the patients treated with 30&nbsp;µg/day had values of 25OHD &gt; 30&nbsp;ng/ml. Handgrip strength showed a modest but progressive increase which reached the statistical significance in the 30&nbsp;µg/day group. This latter group also presented a modest and non-significant decrease in serum levels of myostatin. Conclusions: Calcifediol is able to rapidly normalize the vitamin D deficiency, and the 30&nbsp;µg daily dosage could be suggested in those patients who need to rapidly reach optimal 25OHD levels. Moreover, the 6-month treatment with calcifediol at a dose of 30&nbsp;µg results in a modest but significant increase in upper limb strength

Relationship of sex hormones with bone turnover markers, bone ultrasounds and BMD at multiple sites in men and women

Objectives: Sex steroids play an important role in the regulation of bone turnover in males and females. However, the role of physiological variations in androgen and estrogen levels on bone metabolism in elderly subjects is not clearly understood. Materials and Methods: We assessed circulating sex hormone levels and sex hormone binding globulin (SHBG) in 1110 males and females (aged >50years), participating in the epidemiologic project “Siena Osteoporosi”. For each subject we evaluated bone mineral density at the spine, hip and right hand (BMD, DEXA), ultrasound parameters at phalanxes (amplitude dependent speed of sound [AD-SoS], bone transmission time [BTT]; ultrasound bone profile index [UBPI] by Bone Profiler-IGEA), and serum CTX and bone alkaline phosphatase (BALP), as markers of bone turnover. Serum testosterone (T), estradiol (E), sex-hormone binding globulin (SHBG), 25-hydroxyvitamin D (25OHD), and parathyroid hormone (PTH) were also measured in all subjects. The free androgen index (FAI) and free estrogen index (FEI), as a measure of free hormone levels, were calculated as the ratios between total hormone levels and SHBG. Results: Both in males and in postmenopausal females we demonstrated a progressive decrease in serum FEI and FAI levels, mainly due to parallel increase in SHBG. Interestingly, in osteoporotic subjects of both sexes we observed decreased FEI levels and increased SHBG with respect to non osteoporotic subjects, without any significant difference concerning testosterone or FAI levels. Both BMD at different sites and AD-SoS or UBPI were inversely associated with age. No significant correlation was found between BTT and age. Moreover, among QUS parameters BTT showed the highest correlation with hand-BMD (r=0.68; p<0.001). The correlation coefficients between AD-SoS, BTT and UBPI with hand and axial BMD were all significant (p<0.001) but low, ranging from 0.25 to 0.44. Both FEI and SHBG serum levels were inversely correlated with AD-SoS, BTT and UBPI. Conclusions: The production of estrogen by androgenic precursors plays an important role for bone health in postmenopausal females as well as in elderly males. Moreover, ultrasound parameters such as BTT and AD-SoS could improve the identification of subjects with reduced BMD both at hand and the axial skeleton

Longitudinal association between sex hormone levels, bone loss and bone turnover in elderly men.

Male osteoporosis is an increasingly important health problem. It is known that sex steroid hormones play an important role in regulating bone turnover and bone mass in males as well as in females. However, the exact mechanism of bone loss in men remains unknown. In the present study, 200 elderly men (age range, 55-85 yr) were followed for 4 yr to evaluate the relationships between hormone levels, bone turnover markers, bone mineral density, and rates of bone loss. Femoral and lumbar bone mineral density, bone ultrasound parameters at the os calcis, serum testosterone (T), serum estradiol (E(2)), SHBG levels, and bone turnover markers (urinary crosslaps and bone alkaline phosphatase) were evaluated for each man at enrollment and 4 yr afterward. The free androgen index (FAI) and free estrogen index (FEI) as well as measures of the bioavailable sex hormones [calculated bioavailable E(2) (c-bioE(2)) and T (c-bioT)] were calculated from total hormone levels and SHBG. In the total population, T, c-bioT, c-bioE(2), FAI, and FEI, but not E(2), decreased significantly with age, whereas SHBG increased significantly. Subjects with FEI, c-bioE(2), and E(2) levels below the median showed higher rates of bone loss at the lumbar spine and the femoral neck as well as higher speed-of-sounds decrease at the calcaneus with respect to men with FEI, c-bioE(2), and E(2) levels above the median. Serum bone alkaline phosphatase and urinary crosslaps were significantly higher in men with FEI, c-bioE(2), and E(2) in the lower quartile than in men with FEI, c-bioE(2), and E(2) levels in the higher quartile. No statistically significant differences were observed in relation to T, c-bioT, or FAI levels. Finally, the ratio between E(2) and T, an indirect measure for aromatase activity, increased significantly with age and was higher in normal than in osteoporotic subjects. In conclusion, results from the present study indicate an important role of estrogens, and particularly of the ability to aromatize T to E(2), in the regulation of bone loss and bone metabolism in elderly me